pandas comparison raises TypeError: cannot compare a dtyped [float64] array with a scalar of type [bool]
& has higher precedence than ==. Write:
dataframe
How to convert index of a pandas dataframe into a column
either: or, .reset_index: so, if you have a multi-index frame with 3 levels of index, like: and you want to convert the 1st (tick) and 3rd (obs) levels in the index into columns, you would do:
Move column by name to front of table in pandas
We can use ix to reorder by passing a list: Another method is to take a reference to the column and reinsert it at the front: You can also use loc to achieve the same result as ix will be deprecated in a future version of pandas from 0.20.0 onwards:
Read data (.dat file) with Pandas
You can use parameter usecols with order of columns: Edit: You can use separator regex – 2 and more spaces and then add engine=’python’ because warning: ParserWarning: Falling back to the ‘python’ engine because the ‘c’ engine does not support regex separators (separators > 1 char and different from ‘\s+’ are interpreted as regex); you … Read more
if else function in pandas dataframe
You can use numpy.where: Error is better explain here. Slowier solution with apply, where need axis=1 for data processing by rows: Also is possible use loc, but sometimes data can be overwritten:
Sample random rows in dataframe
First make some data: Then select some rows at random:
Find the unique values in a column and then sort them
sorted(iterable): Return a new sorted list from the items in iterable. CODE OUTPUT
How to add pandas data to an existing csv file?
You can specify a python write mode in the pandas to_csv function. For append it is ‘a’. In your case: The default mode is ‘w’.
Coalesce values from 2 columns into a single column in a pandas dataframe
use combine_first():
R error: “New Column would leave holes after existing columns”
You can index RT with is.na(ACC) like this. This answer will work if RT and ACC have the same dimension.